1. Field of the Invention
The present invention relates generally to wrenches and similar mechanical devices having adjustable jaws. More particularly, the present invention comprises a gripping device having at least one pair of opposed jaws moving in a linear guide track with the separation of the jaws being driven by a cam track in a torque application component which rotates relative to the base plate.
2. Description of the Related Art
A single wrench or gripping tool having adjustably positionable jaws to grip various sizes or diameters of bolt heads, nuts, and other fittings has been a goal of the toolmaking industry for decades. Various devices have been developed in the past, with these devices having various degrees of success in industry and the marketplace.
A well-known example of such an adjustable tool is the Crescent® wrench, having one fixed jaw and a single, linearly adjustable jaw extending from the fixed jaw and handle. Due to the unitary, monolithic construction of the fixed jaw and handle, the device must be operated essentially like a conventional open-end wrench. A relative of such adjustable wrenches is the pipe wrench or “monkey wrench,” which also has a linearly adjustable jaw opposite a fixed jaw and handle. The pipe wrench typically includes an intentionally large amount of play between the two jaws, which causes the movable jaw to be biased toward the fixed jaw and to grip the fastener head or fixture more tightly therebetween when torque is applied toward the movable jaw. Reversing the direction of pressure on the handle releases the grip, allowing the pipe wrench to be rotated about the workpiece to accomplish somewhat the same function as provided by a ratcheting wrench. However, the pipe wrench has sharp teeth of the gripping jaws, which may damage hexagonal nuts and other such fasteners, and the span of the jaws varies in steps, rather than continuously, due to use of a rack for adjustment of the span.
Many wrenches and gripping devices provide a ratcheting action, in which a ratchet may be swung arcuately back and forth with the ratchet releasing in one direction and gripping in the opposite direction to apply unidirectional rotational movement to the adjustable jaws. However, the present inventor is unaware of any devices which provide automatic adjustment of the jaw span as the attached ratchet or similar device is rotated, and which also provides a tighter grip on the workpiece between the jaws as more torque is applied to the ratchet handle with the simplicity and effectiveness of the gripping device of the present invention. Thus, an automatically adjusting gripping device solving the aforementioned problems is desired.